耕地利用转型碳排放时空分异特征与形成机理研究

Spatio-temporal Differentiation Characteristics and Formation Mechanism of Carbon Emission from Cultivated Land Use Transformation

为揭示耕地利用转型的碳排放时空分异特征,以松花江流域哈尔滨段为例,基于网格单元法和碳排放系数,测度1990—2020年耕地利用转型的碳排放强度,并借助重心分析、探索性空间数据分析、冷热点分析工具和地理探测器等研究方法揭示耕地利用转型的碳排放空间异质性与形成机理。结果表明:1990—2020年耕地面积呈下降趋势,耕地与建设用地、林地之间的转型最为剧烈,耕地主要转型为建设用地。1990—2020年耕地利用转型碳排放量呈上升趋势,由1990—2000年的3704.12 t增加到2010—2020年的35656.29 t,增加了近8.63倍,耕地利用转型碳排放最终呈现为碳源形式。1990—2020年耕地利用转型碳排放重心基本保持稳定,向东移动了15.17 km,其中1990—2010年重心移动距离最大,呈现东北地区碳排放恶化,而西南地区碳排放明显改善的特点。1990—2020年耕地利用转型碳排放非随机分布,具有较强的空间集聚性,热点区主要围绕南岗区向周围边界扩散,冷点区零星点状分布在东南部地区。与城镇中心距离是耕地利用转型碳排放的主控因子,各因子之间交互作用以双因子增强为主,其中土地利用程度与年平均降水量、与城镇中心距离之间的相互作用解释力较强,耕地利用转型碳排放空间分异特征是多因子共同作用的结果。

In order to reveal the temporal and spatial differentiation characteristics of carbon emissions from cultivated land use transition,taking Harbin section of Songhua River Basin as an example,the carbon emission intensity of cultivated land use transition from 1990 to 2020 was measured based on the grid element method and carbon emission coefficient.In addition,the means of gravity center analysis,exploratory spatial data analysis,cold and hot spot analysis tools and geodetector were implemented to reveal the spatial heterogeneity and formation mechanism of carbon emissions from cultivated land use transition.The results showed that the cultivated land area demonstrated a downward trend in 1990—2020,and the conversion between cultivated land and construction land,forest land was the most dramatic,and cultivated land mainly converted into construction land.The carbon emission of cultivated land use transformation showed an upward trend in 1990—2020,from 3704.12 t in 1990—2000 to 35656.29 t in 2010—2020 with an increase of nearly 8.63 times.The carbon emission of cultivated land use transformation eventually appeared as a carbon source.From 1990 to 2020,the carbon emission center of arable land use transformation remained basically stable,moving 15.17 km to the east,of which the center of gravity moved the longest from 1990 to 2010.Overall the carbon emissions in the northeast region continue to deteriorate,while the carbon emissions in the southwest region were improved significantly.In 1990—2020,the carbon emissions from cultivated land use transformation were non randomly distributed,but had strong spatial agglomeration.The hot spots mainly spread around Nangang District to the surrounding boundary,and the cold spots were scattered in the southeast.Urban center distance was the main factor of carbon emission for cultivated land use transformation,and the interaction between various factors was mainly enhanced by two factors.Among them,the interaction between land use degree,and annual average precipitation,urban center distance had strong explanatory power.The spatial differentiation characteristics of carbon emission for cultivated land use transformation were the result of multi-factor interaction.